Carbide feed mechanism for acetylene generators



8- 1950 H. HOOPER CARBIDE FEED MECHANISM FOR ACETYLENE GENERATORS Filed June 24, 1948 INVENTOR H ARR Y H O O P E R ATTORNEY S Patented Aug. 22, 1950 CARBIDE FEED MECHANISM FOR ACETYLENE GENERATORS Harry Hooper, New York, N. Y., assignor to Air Reduction Company, Incorporated, a corporation of New York Application June 24, 1948, Serial No. 34,916

8 Claims.

This invention relates to acetylene generators of the carbide to water type and more particularly to the carbide feed mechanism of such generators.

A common type of carbide feed mechanism for carbide to water acetylene generators includes a plate or disc or other movable feed element which controls the delivery of carbide from a hopper into the water in the generator and which is operated by or in response to the movement of a diaphragm: The diaphragm is exposed on one side to the pressure of the acetylene produced in the generator and is usually spring loaded at its opposite side, so that when the force of the loading spring predominates over the pressure of the acetylene on the diaphragm, carbide is fed to the generator until the increase in the amount of generated acetylene causes the acetylene pressure to predominate over the force of the loading spring and thereby discontinue the feeding of the carbide.

Carbide feed mechanisms having such a spring loaded diaphragm are inefficient because the spring force varies as the spring is compressed or expanded when the generator pressure changes and the diaphragm moves. It has been proposed to overcome this objection by substituting for the diaphragm loading spring a compressed gas held at a constant pressure. By thus providing a constant diaphragm load the diaphragm moves more rapidly in response to pressure variations in the generated acetylene and the diaphragm movements more accurately reflect such pressure variations.

The principal object of this invention is to provide a carbide feed mechanism of the diaphragm operated or diaphragm controlled type in which the diaphragm loading is a constantforce, as in the case of gas loading, but is produced by simple mechanical means as distinguished from gaseous means.

Another object is to provide an improved carbide feed mechanism which will permit the use of large flexible diaphragms so that the effect of diaphragm stiffness and variations in effective area will be negligible in the operation of the mechanism.

According to the invention the carbide feed element which controls the delivery of carbide from the feed hopper to the water in the generator is diaphragm actuated or controlled and the diaphragm loading force is the constant buoyant force of a float that is normally completely submerged in a body of liquid, the body of liquid preferably being for convenience the water in the generator.

The invention is illustrated in the accompany- 2 ing drawing the single figure of which is a vertical section through the hopper and carbide feed mechanism of an acetylene generator embodying the invention, a few of the parts being shown in side elevation.

Referring to the drawing, the carbide hopper of a carbide to water type acetylene generator is shown at In. The carbide is usually in the form of small particles, as is well understood in the art. The hopper has a downwardly sloping bottom I I at the center of which is a discharge opening i2. Carbide in the hopper is free to move downwardly through the opening l2 into a spout l3 whose bottom opening is controlled by a feed plate or feed valve It. When the feed valve it is opened carbide is discharged directly from the spout l3 into the water IS in the generating chamber E6 of the generator.

The hopper ii is charged with carbide through an opening provided at the top of the hopper which is sealed by a cover plate ll removably held in place by a yoke l8 and clamping screw IS.

The feed valve H3 is secured to a rod 20 which extends upwardly through a casing 2i Supported in the feed hopper by pipes 22 and 23. The lower end of the casing 2! is closed by a diaphragm 24 which is clamped at its periphery to the casing in a gas-tight manner by a clamping ring 25. The upper end of this casing is similarly closed by another diaphragm 26 which is clamped at its periphery to the casing in a gas-tight manner by means of a clamping ring 21. Each of the diaphragms is clamped at its center portion to the valve rod 20, the upper diaphragm being clamped to the rod by clamping plates 28 and the lower 2diaphragm being clamped to it by clamping plates The under side of the diaphragm 24 and the upper side of the diaphragm 26 are exposed to the pressure of the acetylene produced in the generator. The space within the casing between the two diaphragms is vented to the atmosphere by the pipe 22 so this space is always at atmospheric pressure.

The upper diaphragm 26 is made smaller than the lower diaphragm 24 so that the predominance of the acetylene pressure acting on the lower face of the larger diaphragm 24 over the acetylene pressure acting on the upper face of the smaller diaphragm 26 tends to move the valve rod 20 upwardly and close the feed valve I4.

When the generator is not in operation, the feed valve I4 is held in its raised or closed position by means of a cam 30 which acts against the lower face of the lower one of the two clamping plates 28 that clamp the diaphragm 26 to end out a shaft 3| which is Journalled to rotate in the pipe 23 in a gas-tight manner and which extends to a'point outside of the hopper where it is connected to a handle it. When it is desired to start the generation of acetylene the handle I! is partially rotated to turn the cam 80 to a new position which will allow the valve rod it to move downwardly and open the feed valve II. at the full open position of the feed valve ll, an excessive flow of carbide from the feed hopper into the water in the generator is prevented by a disc II on the valve rod which then closes the opening I! in the bottom of the hopper. The need for restricting the flow of carbide from the hopper by means of the disc 3! exists only at the start of acetylene generation when no gas pressure exists in the generator. As soon as the valve rod 20 has been lowered by turning the handle 32, carbide falls rapidly into the generating chamber It since there is no acetylene pressure acting on the diaphragms tending to raise them and therefore the feed valve is at its lowest position. If it were not for the disc I3, by the time the feed valve I4 is eventually raised by the acetylene pressure on the diaphragms an excessive amount of carbide would have been fed to the generating chamber, causing a further rise in pressure of the acetylene or a so-called after generation" which is undesirable because of the possibility of wasting gas through the generator relief valve. The disc 33 causes the carbide to be delivered to the generating chamber in an amount which is no greater than the amount that can be retained in the spout it below the opening I! in the hopper.

A hood or inverted cone 34 is mounted over the upper diaphragm It to protect it from the carbide in the hopper, but this protecting hood 4 would rise and fall with the change in the water level, thereby changing the loading force exerted on the diaphragm 24. By positioning the float so that it is normally below the level of does not prevent access of some of the generated acetylene to the upper side of the diaphragm. A convenient way of mounting the hood 34 so that it will protect the diaphragm and still allow access of some of the acetylene to the upper side of the diaphragm is to provide downwardly extending lugs or ears 35 on the lower edge of the hood which are fastened to the sides of the easing II in such a way that a gap exists between the lower edge of the hood and the upper end of the casing 2| through which acetylene can pass into the interior of the hood.

A rod" is secured to and extends downwardly from the feed valve I4 and is pivoted atll to one end of a lever is which in turn is pivotally mounted intermediate its ends on a pivot 30 supported in any suitable way in the generatin chamber. The other end of the lever 38 has secured to it a float II which is normally completely submerged in a body of liquid which is preferably the water II in the generating chamber of the generator. The buoyancy of the water on the float, i. e. the buoyant force of the float, is thus transmitted through the lever II to the downwardly extending rod 16 on the feed valve and tends to move this rod and the feed valve downwardly to open the valve. This force is of course transmitted to the diaphragm 24 and acts on it in opposition to the acetylene pressure acting on its under side and therefore constitutes a loading force for the diaphragm. It is important that during the normal operation of the generator the float 40 be located at a level below that of the water in the generator because the water in the generator the continual tendency of the water to raise the float produces a constant loading force on the diaphragm. However, should the amount of water in the generator be so far reduced as to bring the water level down to a point where the water permits the float to descend, then the float will close the feed valve it. Therefore, by positioning the float at a level which corresponds to the level below which it is not safe for the water to recede the float will also serve as a safety device which prevents feed of carbide when the water drops belowasafe level.

It should be understood that a single diaphragm could be used in place of the two diaphragms above described. In other words the upper diaphragm 28 could be omitted and the top of the casing It could be closed so that all of v the acetylene pressure acting on the under side of the .diaphragm 24 is utilized in lifting the valve rod 2|. However, the use of two diaphragm of a diflerent size is preferred since each of the diaphragms may then be of larger diameter than if only one were used because it is only the differential area of the two diaphragms that is instrumental in closing the feed valve. The advantage of using diaphragms of relatively large diameter is that they have greater flexibility and therefore have a more sensitive response. Moreover, if only one diaphragm were used this would necessitate the use of a float of larger undesirable size to produce the additional required loading force on the diaphragm. It is evident that the two diaphragms may be so related in size that a comparatively small float may be used to balance the net effect of the acetylene pressure acting on the two diaphragms at the desired generator pressure.

The relation between the differential area of the two diaphragms and the float I will depend of course on the relative lengths of the two lever arms of the pivoted lever 38. If the length of the lever arm connected to the rod 38 is represented by a and the length of the other lever arm is represented by b the proper relationship between all of the factors to produce a condition of equilibrium at the delivery pressure of the generator (neglecting the weight of the parts and other effects such as friction) may be expressed by the following equation: Generator gas pressurexdifl'erential diaphragm areaxlever arm a=buoyant force of floatxlever arm I).

It will now be seen that the buoyant force of the completely submerged float will produce a loading force on the main diaphragm which remains constant at all times and therefore the carbide feed mechanism will operate practically uniformly throughout the entire displacement of the carbide feed valve which would not be true if a spring were employed to produce the diaphragm loading.

I claim:

1. In a carbide to water acetylene generator, carbide feed mechanism comprising a carbide hopper, a movable element controlling the delivery of carbide from the hopper to the water in the generator. a diaphragm, means whereby the diaphragm controls the movement of said movable element, said diaphragm being exposed at one side to the pressure of the acetylene proif it floated on the surface of the water the float duced in the generator, means for exerting an oppositely acting constant force on the diaphragm comprising a lighter-than-water float normally completely submerged in a body of liquid, and connections arranged to transmit the buoyant force of the float to a part movable with the diaphragm so that such force acts on the diaphragm in opposition to the pressure of the generated acetylene.

2. In a carbide to water acetylene generator, carbide feed mechanism comprising a carbide hopper, a feed valve controlling the delivery of carbide from the hopper to the water in the generator, a diaphragm, connections from the diaphragm to said feed valve whereby the diaphragm controls the opening and closing of the feed valve, said diaphragm being exposed at one side to the pressure of the acetylene produced in the generator so that such pressure tends to produce movement of the diaphragm in a. direction that will effect closing of said feed valve, a lighter-than-water float normally completely submerged in a body of liquid, and connections from the float to a part movable with the diaphragm and arranged to transmit the buoyant force of the float to the diaphragm so that the buoyant force tends to produce movement of the diaphragm in a direction that will efl'ect opening of the feed valve.

3. Carbide feed mechanism in accordance with claim 1 in which said float is arranged to be normally completely submerged in the body of water in the generator.

4. Carbide feed mechanism in accordance with claim 2in which said float is arranged to be normally completely submerged in the body of water in the generator.

5. In a carbide to water acetylene generator, carbide feed mechanism comprising a carbide hopper having a discharge opening in its lower portion, a vertically movable feed valve controlling said discharge opening and the delivery of carbide from the hopper to the water in the generator, a diaphragm exposed at one side to the pressure of the acetylene produced in the generator so that such pressure tends to produce movement of the diaphragm in one direction, connections between the diaphragm and the feed valve for positively lifting the valve to close it when the diaphragm is moved by the acetylene. pressure in said direction, a rod connected to said feed valve and extending downwardly from it, a lighter-than-water float normally completely submerged in the body of water in the generator below the feed valve and operatively connected to said rod so that the buoyancy of the water on the float produces a constant downward force on said rod which tends to lower the feed valve and open it and which is transmitted to the diaphragm so that it tends to move the diaphragm in a direction opposite to that in which the acetylene pressure tends to move it.

6. In a carbide to water acetylene generator, carbide feed mechanism comprising a carbide hopper having a discharge opening in its lower portion, a vertically movable feed valve controlling said discharge opening and the delivery of carbide from the hopper to the water in the generator, a horizontally disposed diaphragm above the feed valve exposed at its under side to the pressure of the acetylene produced in the generator so that such pre-ure tends to move the diaphragm upwardly, a rod connecting the diaphragm and feed valve for positively moving the valve upwardly to close it when the diaphragm is moved upwardly by the acetylene pres- 75 2,885,087

sure, a rod connected to said feed valve and extending "downwardly from it, a lighter-thanwater float normally completely submerged in the body of water in the generator below the feed valve, and a lever pivoted intermediate its ends one end of which is connected to the float and the other end of which is pivotally connected to said last-named rod whereby the buoyancy of the water on the float produces a constant force on said rod which tends to move the diaphragm and feed valve downwardly and open the valve.

7. In a carbide to water acetylene generator, carbide feed mechanism comprising a carbide hopper having a dicharge opening in its lower portion, a vertically movable feed valve controlling said discharge opening and the delivery of carbide from the hopper to the water in the generator, a pair of spaced diaphragms connected to each other and to said feed valve, one face of one of the diaphragms and the opposite face of the other diaphragm being exposed to the pressure of the acetylene produced in the generator, one of the diaphragms having a larger area thus exposed to the acetylene pressure than the other and adapted when moved by the predominance of acetylene pressure acting on it to produce movement of the diaphragms in a direction that will effect lifting and closing of the feed valve, a lighter-than-water float normally completely submerged in a body of liquid, and connections arranged to transmit the buoyant force of the float to a part movable with the diaphragms so that such force acts on them in opposition to said predominance of acetylene pressure and tends to produce movement of the diaphragms in a direction that will effect lowering and opening of the feed valve.

8. In a carbide to water acetylene generator, carbide feed mechanism comprising a carbide hopper having a discharge opening in its lower portion, a vertically movable feed valve controlling said discharge opening and the delivery of carbide from the hopper to the water in the generator, a pair of spaced diaphragms connected to each other and to said feed valve, the outer face of each diaphragm being exposed to the pressure of the acetylene produced in the generator, one of the diaphragms having a larger area thus exposed to the acetylene pressure than the other and adapted when moved by the predominance of acetylene pressure acting on it to produce movement of the diaphragms in a direction that will effect lifting and closing of the feed valve, a lighter-than-water float normally completely submerged in a body of liquid, and connections arranged to transmit the buoyant force of the float to a part movable with the diaphragms so that such force acts on them in opposition to said predominance of acetylene pressure and tends to produce movement of the diaphragms in a direction that will eflect lowering and opening of the feed valve.

, HARRY HOOPER.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,085,490 Salazar Jan. 27, 1914 1,799,589 Irwin Apr. 7, 1931 1,809,521 Mandeville June 9, 1931 1,995,968 De Motto Mar. 26, 1935 La Force Sept. 18, 1949 

1. IN A CARBIDE TO WATER ACETYLENE GENERATOR, CARBIDE FEED MECHANISM COMPRISING A CARBIDE HOPPER, A MOVABLE ELEMENT CONTROLLING THE DELIVERY OF CARBIDE FROM THE HOPPER TO THE WATER IN THE GENERATOR, A DIAPHRAGM, MEANS WHEREBY THE DIAPHRAGM CONTROLS THE MOVEMENT OF SAID MOVABLE ELEMENT, SAID DIAPHRAGM BEING EXPOSED AT ONE SIDE TO THE PRESSURE OF THE ACTYLENE PRODUCED IN THE GENERATOR, MEANS FOR EXERTING AN OPPOSITELY ACTING CONSTANT FORCE ON THE DIAPHRAGM COMPRISING A LIGHTER-THAN-WATER FLOAT 